William Ames (Latin: Guilielmus Amesius) (1576 – 14 November 1633) was an English Protestant divine, philosopher, and controversialist. He spent much time in the Netherlands, and is noted for his involvement in the controversy between the Calvinists and the Arminians.

He was popular in the university, and in his own college. One of Ames's sermons became historical in the Puritan controversies. It was delivered in the university Church of St Mary the Great, Cambridge on 21 December 1609, and in it he rebuked sharply "lusory lotts" and the "heathenish debauchery" of the students during the Twelve Days of Christmas.

A partisan election, however, had led to the mastership at Christ's going to Valentine Carey. He quarrelled with Ames for disapproving of the surplice and other outward symbols. Ames's vehemence led to his being summoned before the Vice-Chancellor, who suspended him "from the exercise of his ecclesiastical function and from all degrees taken or to be taken."[3][4]

Ministry in Holland

He left Cambridge, and was offered a lecturer position at Colchester, but George Abbot, the Bishop of London, went against the wishes of the local corporation, and refused to grant institution and induction.[5] Similar rebuffs awaited him elsewhere, and in 1607 he travelled with Reverend Robert Parker over to the Netherlands, helped by English merchants who wished him to controvert the supporters of the English church in Leiden. At Rotterdam, clad in the fisherman's habit donned for the passage, he opposed Grevinchovius (Nicholas Grevinckhoven, d. 1632), minister of the Arminian (Remonstrant) church, and overwhelmed him with his logical reasoning from Phillipians ii. 13, "It is God that worketh in us both to will and to do." This dispute made his name in the Netherlands.